Manufacture of azo dyestuffs



Patented Sept. 1 1931 pairs!) STATES PATENT OFFICE PAUL LAEUGER, F BAsEL, SWITZERLAND, ASSIGNOR TO THE FIRM on J. R. GEIGY s. A., or BASEL, SWITZERLAND MANUFACTURE OF AZO DYESTUFES .No Drawing. Application filed June 27, 1929, Serial No. 374,290, and in Switzerland July 30, 1928.

thane-3carboxylic acid of the formula:

OHP 3 4 OH COOH The product thus obtained dyes Wool,

when after-chromated, a yellow to orange tint of remarkable fastness.

on the methyl pyrazolone from 4-amino-4- hydroXy-5-methyl-diphenyl methane-dearboxylic acid, and as diazo compound the l-diazo benzenel-sulphonic acid is preferably used, but it is also possible to employ another diazo-compound, such as for example 1-diazobenzene-3-sulphonic acid, 2-diazo- 4c-nitro-l-phenol, 2-diazo-4-chlorine-l-phenol, aniline-2:5-disulphonic acid, paraamino-salicylic acid, ortho-amino-salicylicsulphonic acid and so on.

The following example illustrates the process, the parts being by weight:

17.3 parts of sulphanilic acid are diazotized and coupled in weakly soda-alkaline solution with 33.8 parts of the methyl-pyrazolone from t-amino hydroxy 5 methyldiphenyl methane-3-carboxylic acid of the formula:

on o=N 5 3- N 4 on 4 OH CHz-OO s coon Advantageously, the coupling is eifected lVhen the copulation is achieved, the mass is warmed up and the formed dyestulf is salted out and ,dried. The dyestuff has the formula:

/ GOOH and constitutes a brown-yellow powder dyeing WOOl in acid bath a beautiful yellow showing, when being after-chromated, excellent properties of fastness.

The methyl pyrazolone from 4-amino-4;- hydroX-y-5-methyl-dinhenyl methane 3-carboxylic acid can be obtained by treating the corresponding diazo-compound with sodium sulphite according to a known method and condensing the 4-hydrazino--hydroxy-5- methyl-diphenyl methane-3-carboxylic acid with aceto-acetic acid ester in acetic acid solution. The pyrazolone thus obtained consti- CH ;C=N

1 N 4' CH2 4 on Hz-CO 3 a fusion point of 228 The dyestufi' obtained according to this modification has the formula:

and dyes wool in an acid bath orange tints with a somewhat brownish shade. This orange dyeing is Very fast.

What I claim is 2- 1. A process for the manufacture of azodyestuffs, consisting in coupling a diazocompound of the phenyl series with the methyl pyrazolone from 4-amino-4-hydroxydiphenyl methane-3-carboxylic acid of the formula:

COOH

wherein X represents a hydrogen or methylgroup.

2. A process for the manufacture of an azo-dyestuff, consisting in coupling the 1- diazobenzene4-sulphonic acid with the methyl pyrazolone from L-amino-4-hydr0Xy-5-methyl diphenyl methane-3-carboxylic acid of the formula:

on -C --N r N 4' on. d 4 OH GHQ-CO 3 00011 3. As a new article of manufacture, the herein described dyestuff having the formula \CH-C-OH U I H a o 0 N 30311 N OOOH/ on,

and which is obtained by coupling the 1- diazobenzene-4-sulphonic acid with the methyl pyrazolone from 4-amino-4-hydroxy 5 methyl diphenyl methane- 3- carboXylic acid of the formula:

ooorr said dyestuff dyeing Wool, when after-chromated, yellow tints of remarkable fastness.

In witness whereof I have hereunto signed 1 my name this 17th day of June, 1929.

PAUL LAEUGER. 

